1 files changed, 349 insertions, 0 deletions
diff --git a/third_party/python/fluent.syntax/fluent/syntax/ast.py b/third_party/python/fluent.syntax/fluent/syntax/ast.py
new file mode 100644
index 0000000000..7ad5d611d6
--- /dev/null
+++ b/third_party/python/fluent.syntax/fluent/syntax/ast.py
@@ -0,0 +1,349 @@
+# coding=utf-8
+from __future__ import unicode_literals
+import re
+import sys
+import json
+import six
+
+
+def to_json(value, fn=None):
+    if isinstance(value, BaseNode):
+        return value.to_json(fn)
+    if isinstance(value, list):
+        return list(to_json(item, fn) for item in value)
+    if isinstance(value, tuple):
+        return list(to_json(item, fn) for item in value)
+    else:
+        return value
+
+
+def from_json(value):
+    if isinstance(value, dict):
+        cls = getattr(sys.modules[__name__], value['type'])
+        args = {
+            k: from_json(v)
+            for k, v in value.items()
+            if k != 'type'
+        }
+        return cls(**args)
+    if isinstance(value, list):
+        return list(map(from_json, value))
+    else:
+        return value
+
+
+def scalars_equal(node1, node2, ignored_fields):
+    """Compare two nodes which are not lists."""
+
+    if type(node1) != type(node2):
+        return False
+
+    if isinstance(node1, BaseNode):
+        return node1.equals(node2, ignored_fields)
+
+    return node1 == node2
+
+
+class BaseNode(object):
+    """Base class for all Fluent AST nodes.
+
+    All productions described in the ASDL subclass BaseNode, including Span and
+    Annotation.  Implements __str__, to_json and traverse.
+    """
+
+    def clone(self):
+        """Create a deep clone of the current node."""
+        def visit(value):
+            """Clone node and its descendants."""
+            if isinstance(value, BaseNode):
+                return value.clone()
+            if isinstance(value, list):
+                return [visit(child) for child in value]
+            if isinstance(value, tuple):
+                return tuple(visit(child) for child in value)
+            return value
+
+        # Use all attributes found on the node as kwargs to the constructor.
+        return self.__class__(
+            **{name: visit(value) for name, value in vars(self).items()}
+        )
+
+    def equals(self, other, ignored_fields=['span']):
+        """Compare two nodes.
+
+        Nodes are deeply compared on a field by field basis. If possible, False
+        is returned early. When comparing attributes and variants in
+        SelectExpressions, the order doesn't matter. By default, spans are not
+        taken into account.
+        """
+
+        self_keys = set(vars(self).keys())
+        other_keys = set(vars(other).keys())
+
+        if ignored_fields:
+            for key in ignored_fields:
+                self_keys.discard(key)
+                other_keys.discard(key)
+
+        if self_keys != other_keys:
+            return False
+
+        for key in self_keys:
+            field1 = getattr(self, key)
+            field2 = getattr(other, key)
+
+            # List-typed nodes are compared item-by-item.  When comparing
+            # attributes and variants, the order of items doesn't matter.
+            if isinstance(field1, list) and isinstance(field2, list):
+                if len(field1) != len(field2):
+                    return False
+
+                for elem1, elem2 in zip(field1, field2):
+                    if not scalars_equal(elem1, elem2, ignored_fields):
+                        return False
+
+            elif not scalars_equal(field1, field2, ignored_fields):
+                return False
+
+        return True
+
+    def to_json(self, fn=None):
+        obj = {
+            name: to_json(value, fn)
+            for name, value in vars(self).items()
+        }
+        obj.update(
+            {'type': self.__class__.__name__}
+        )
+        return fn(obj) if fn else obj
+
+    def __str__(self):
+        return json.dumps(self.to_json())
+
+
+class SyntaxNode(BaseNode):
+    """Base class for AST nodes which can have Spans."""
+
+    def __init__(self, span=None, **kwargs):
+        super(SyntaxNode, self).__init__(**kwargs)
+        self.span = span
+
+    def add_span(self, start, end):
+        self.span = Span(start, end)
+
+
+class Resource(SyntaxNode):
+    def __init__(self, body=None, **kwargs):
+        super(Resource, self).__init__(**kwargs)
+        self.body = body or []
+
+
+class Entry(SyntaxNode):
+    """An abstract base class for useful elements of Resource.body."""
+
+
+class Message(Entry):
+    def __init__(self, id, value=None, attributes=None,
+                 comment=None, **kwargs):
+        super(Message, self).__init__(**kwargs)
+        self.id = id
+        self.value = value
+        self.attributes = attributes or []
+        self.comment = comment
+
+
+class Term(Entry):
+    def __init__(self, id, value, attributes=None,
+                 comment=None, **kwargs):
+        super(Term, self).__init__(**kwargs)
+        self.id = id
+        self.value = value
+        self.attributes = attributes or []
+        self.comment = comment
+
+
+class Pattern(SyntaxNode):
+    def __init__(self, elements, **kwargs):
+        super(Pattern, self).__init__(**kwargs)
+        self.elements = elements
+
+
+class PatternElement(SyntaxNode):
+    """An abstract base class for elements of Patterns."""
+
+
+class TextElement(PatternElement):
+    def __init__(self, value, **kwargs):
+        super(TextElement, self).__init__(**kwargs)
+        self.value = value
+
+
+class Placeable(PatternElement):
+    def __init__(self, expression, **kwargs):
+        super(Placeable, self).__init__(**kwargs)
+        self.expression = expression
+
+
+class Expression(SyntaxNode):
+    """An abstract base class for expressions."""
+
+
+class Literal(Expression):
+    """An abstract base class for literals."""
+    def __init__(self, value, **kwargs):
+        super(Literal, self).__init__(**kwargs)
+        self.value = value
+
+    def parse(self):
+        return {'value': self.value}
+
+
+class StringLiteral(Literal):
+    def parse(self):
+        def from_escape_sequence(matchobj):
+            c, codepoint4, codepoint6 = matchobj.groups()
+            if c:
+                return c
+            codepoint = int(codepoint4 or codepoint6, 16)
+            if codepoint <= 0xD7FF or 0xE000 <= codepoint:
+                return six.unichr(codepoint)
+            # Escape sequences reresenting surrogate code points are
+            # well-formed but invalid in Fluent. Replace them with U+FFFD
+            # REPLACEMENT CHARACTER.
+            return '�'
+
+        value = re.sub(
+            r'\\(?:(\\|")|u([0-9a-fA-F]{4})|U([0-9a-fA-F]{6}))',
+            from_escape_sequence,
+            self.value
+        )
+        return {'value': value}
+
+
+class NumberLiteral(Literal):
+    def parse(self):
+        value = float(self.value)
+        decimal_position = self.value.find('.')
+        precision = 0
+        if decimal_position >= 0:
+            precision = len(self.value) - decimal_position - 1
+        return {
+            'value': value,
+            'precision': precision
+        }
+
+
+class MessageReference(Expression):
+    def __init__(self, id, attribute=None, **kwargs):
+        super(MessageReference, self).__init__(**kwargs)
+        self.id = id
+        self.attribute = attribute
+
+
+class TermReference(Expression):
+    def __init__(self, id, attribute=None, arguments=None, **kwargs):
+        super(TermReference, self).__init__(**kwargs)
+        self.id = id
+        self.attribute = attribute
+        self.arguments = arguments
+
+
+class VariableReference(Expression):
+    def __init__(self, id, **kwargs):
+        super(VariableReference, self).__init__(**kwargs)
+        self.id = id
+
+
+class FunctionReference(Expression):
+    def __init__(self, id, arguments, **kwargs):
+        super(FunctionReference, self).__init__(**kwargs)
+        self.id = id
+        self.arguments = arguments
+
+
+class SelectExpression(Expression):
+    def __init__(self, selector, variants, **kwargs):
+        super(SelectExpression, self).__init__(**kwargs)
+        self.selector = selector
+        self.variants = variants
+
+
+class CallArguments(SyntaxNode):
+    def __init__(self, positional=None, named=None, **kwargs):
+        super(CallArguments, self).__init__(**kwargs)
+        self.positional = [] if positional is None else positional
+        self.named = [] if named is None else named
+
+
+class Attribute(SyntaxNode):
+    def __init__(self, id, value, **kwargs):
+        super(Attribute, self).__init__(**kwargs)
+        self.id = id
+        self.value = value
+
+
+class Variant(SyntaxNode):
+    def __init__(self, key, value, default=False, **kwargs):
+        super(Variant, self).__init__(**kwargs)
+        self.key = key
+        self.value = value
+        self.default = default
+
+
+class NamedArgument(SyntaxNode):
+    def __init__(self, name, value, **kwargs):
+        super(NamedArgument, self).__init__(**kwargs)
+        self.name = name
+        self.value = value
+
+
+class Identifier(SyntaxNode):
+    def __init__(self, name, **kwargs):
+        super(Identifier, self).__init__(**kwargs)
+        self.name = name
+
+
+class BaseComment(Entry):
+    def __init__(self, content=None, **kwargs):
+        super(BaseComment, self).__init__(**kwargs)
+        self.content = content
+
+
+class Comment(BaseComment):
+    def __init__(self, content=None, **kwargs):
+        super(Comment, self).__init__(content, **kwargs)
+
+
+class GroupComment(BaseComment):
+    def __init__(self, content=None, **kwargs):
+        super(GroupComment, self).__init__(content, **kwargs)
+
+
+class ResourceComment(BaseComment):
+    def __init__(self, content=None, **kwargs):
+        super(ResourceComment, self).__init__(content, **kwargs)
+
+
+class Junk(SyntaxNode):
+    def __init__(self, content=None, annotations=None, **kwargs):
+        super(Junk, self).__init__(**kwargs)
+        self.content = content
+        self.annotations = annotations or []
+
+    def add_annotation(self, annot):
+        self.annotations.append(annot)
+
+
+class Span(BaseNode):
+    def __init__(self, start, end, **kwargs):
+        super(Span, self).__init__(**kwargs)
+        self.start = start
+        self.end = end
+
+
+class Annotation(SyntaxNode):
+    def __init__(self, code, arguments=None, message=None, **kwargs):
+        super(Annotation, self).__init__(**kwargs)
+        self.code = code
+        self.arguments = arguments or []
+        self.message = message